Sci'Con's saddle bags are notable for their retention systems. No Velcro straps. The design has been updated to the new Roller 2 mounting system. If you recall the original Roller System (now Roller 1), you start with a plastic cleat that secures to your seat rails with the twist of a knob. Then you install the bag by matching the cleat with the opening in the binding mount. And give it a 1/4 turn. The Roller 2 takes that same idea and adds two tire levers to the design. There's one mount for a tire lever outside the bag, and a mount for a tire lever inside the bag. To make sure the lever slots work, Sci'Con includes the levers. Building the two levers into the design frees up space in the bag, so you can fit more into it.We see the Hippo as holding one or two tubes, a few CO2 cartridges, an inflator, a multi-tool, and some bits and pieces. The bag has a 180-degree zipper around the mouth. There's a single cavity inside. There are two reflective stripes that go from one side of the bag to the other. There's also a reflective design on the Cordura side panels. The rear of the bag has a rubber tab that can fit some small blinky-lights. Taking a ruler to the Sci'Con Hippo 550 Roller 2 saddlebag, it measures 12x7x9cm. The bag capacity is 550 cubic centimeters (33.56 cubic inches). It is Black.